I'm looking at the same sort of issue with our installation. I believe it's supposed to be possible to set up a forum on the front page, and if you've given the role "authenticated users on front page" permissions to post/reply/view etc, then it should work. Or have the logged in user role on the front page be student.
It looks like course forums require enrolment, permission overrides aren't enough.
But it might be handy to have a whole course area and enrol in that anyway -- FAQs, examples, wiki could all also be useful.
Qualifier -- we're using Moodle 2